Catalyst modifiers and their use in the polymerization of olefin(s)

ABSTRACT

The present invention relates to the use of thermally triggered compounds that when used with a polymerization catalyst in a polymerization process results in the controllable generation of one or more catalyst inhibitors that renders the polymerization catalyst substantially or completely inactive.

FIELD OF THE INVENTION

The present invention relates to a method for improving operability in aprocess for polymerizing olefin(s). In particular, the invention isdirected to a method for controlling the kinetics of an olefinpolymerization catalyst utilizing a thermally triggered compound thatundergoes a chemical transformation into one or more catalystinhibitor(s) that inactivate the polymerization catalyst.

BACKGROUND OF THE INVENTION

Advances in polymerization and catalysis have resulted in the capabilityto produce many new polymers having improved physical and chemicalproperties useful in a wide variety of superior products andapplications. With the development of new catalysts the choice ofpolymerization-type (solution, slurry, high pressure or gas phase) forproducing a particular polymer has been greatly expanded. Also, advancesin polymerization technology have provided more efficient, highlyproductive and economically enhanced processes.

Especially illustrative of these advances is the development oftechnology utilizing bulky ligand metallocene catalyst systems.Regardless of these technological advances in the polyolefin industry,common problems, as well as new challenges associated with processoperability still exist. For instance, the tendency for a gas phase orslurry phase process to foul and/or sheet remains a challenge using anyolefin polymerization catalyst.

For example, in a continuous slurry process fouling on the walls of thereactor, which act as a heat transfer surface, can result in manyoperability problems. Poor heat transfer during polymerization canresult in polymer particles adhering to the walls of the reactor. Thesepolymer particles can continue to polymerize on the walls and can resultin a premature reactor shutdown. Also, depending on the reactorconditions, some of the polymer may dissolve in the reactor diluent andredeposit on for example the metal heat exchanger surfaces.

In a typical continuous gas phase process, a recycle system is employedfor many reasons including the removal of heat generated in the processby the polymerization. Fouling, sheeting and/or static generation in acontinuous gas phase process can lead to the ineffective operation ofvarious reactor systems. For example, the cooling mechanism of therecycle system, the temperature probes utilized for process control andthe distributor plate, if affected, can lead to an early reactorshutdown.

Evidence of, and solutions to, various process operability problems havebeen addressed by many in the art. For example, U.S. Pat. Nos.4,792,592, 4,803,251, 4,855,370 and 5,391,657 all discuss techniques forreducing static generation in a polymerization process by introducing tothe process for example, water, alcohols, ketones, and/or inorganicchemical additives; European Patent EP 0 634 421 B1 discussesintroducing directly into the polymerization process water, alcohol andketones to reduce fouling. A PCT publication WO 97/14721 published Apr.24, 1997 discusses the suppression of fines that can cause sheeting byadding an inert hydrocarbon to the reactor; U.S. Pat. No. 5,627,243discusses a new type of distributor plate for use in fluidized bed gasphase reactors; PCT publication WO 96/08520 discusses avoiding theintroduction of a scavenger into the reactor; U.S. Pat. No. 5,461,123discusses using sound waves to reduce sheeting; U.S. Pat. No. 5,066,736and EP-A1 0 549 252 discuss the introduction of an activity retarder tothe reactor to reduce agglomerates; U.S. Pat. No. 5,610,244 relates tofeeding make-up monomer directly into the reactor above the bed to avoidfouling and improve polymer quality; U.S. Pat. No. 5,126,414 discussesincluding an oligomer removal system for reducing distributor platefouling and providing for polymers free of gels; EP-A1 0 453 116published Oct. 23, 1991 discusses the introduction of antistatic agentsto the reactor for reducing the amount of sheets and agglomerates; WO00/66637 discloses the use of a fatty amine to reduce fouling andsheeting; U.S. Pat. No. 4,012,574 discusses adding a surface-activecompound, a perfluorocarbon group, to the reactor to reduce fouling;U.S. Pat. No. 5,026,795 discusses the addition of an antistatic agentwith a liquid carrier to the polymerization zone in the reactor; U.S.Pat. No. 5,410,002 discusses using a conventional Ziegler-Nattatitanium/magnesium supported catalyst system where a selection ofantistatic agents are added directly to the reactor to reduce fouling;U.S. Pat. Nos. 5,034,480 and 5,034,481 discuss a reaction product of aconventional Ziegler-Natta titanium catalyst with an antistat to produceultrahigh molecular weight ethylene polymers; U.S. Pat. No. 3,082,198discusses introducing an amount of a carboxylic acid dependent on thequantity of water in a process for polymerizing ethylene using atitanium/aluminum organometallic catalysts in a hydrocarbon liquidmedium; and U.S. Pat. No. 3,919,185 describes a slurry process using anonpolar hydrocarbon diluent using a conventional Ziegler-Natta-type orPhillips-type catalyst and a polyvalent metal salt of an organic acid.

There are various other known methods for improving operabilityincluding coating the polymerization equipment, for example, treatingthe walls of a reactor using chromium compounds as described in U.S.Pat. Nos. 4,532,311 and 4,876,320; injecting various agents into theprocess, for example PCT Publication WO 97/46599 published Dec. 11, 1997discusses feeding into a lean zone in a polymerization reactor anunsupported, soluble metallocene catalyst system and injectingantifoulants or antistatic agents into the reactor; controlling thepolymerization rate, particularly on start-up; and reconfiguring thereactor design.

Others in the art to improve process operability have discussedmodifying the catalyst system by preparing the catalyst system indifferent ways. For example, methods in the art include combining thecatalyst system components in a particular order; manipulating the ratioof the various catalyst system components; varying the contact timeand/or temperature when combining the components of a catalyst system;or simply adding various compounds to the catalyst system. Thesetechniques or combinations thereof are discussed in the literature.Especially illustrative in the art is the preparation procedures andmethods for producing bulky ligand metallocene catalyst systems, moreparticularly supported bulky ligand metallocene catalyst systems withreduced tendencies for fouling and better operability. Examples of theseinclude: WO 96/11961 published Apr. 26, 1996 discusses as a component ofa supported catalyst system an antistatic agent for reducing fouling andsheeting in a gas, slurry or liquid pool polymerization process; U.S.Pat. No. 5,283,218 is directed towards the prepolymerization of ametallocene catalyst; U.S. Pat. Nos. 5,332,706 and 5,473,028 haveresorted to a particular technique for forming a catalyst by incipientimpregnation; U.S. Pat. Nos. 5,427,991 and 5,643,847 describe thechemical bonding of non-coordinating anionic activators to supports;U.S. Pat. No. 5,492,975 discusses polymer bound metallocene catalystsystems; U.S. Pat. No. 5,661,095 discusses supporting a metallocenecatalyst on a copolymer of an olefin and an unsaturated silane; PCTpublication WO 97/06186 published Feb. 20, 1997 teaches removinginorganic and organic impurities after formation of the metallocenecatalyst itself; PCT publication WO 97/15602 published May 1, 1997discusses readily supportable metal complexes; PCT publication WO97/27224 published Jul. 31, 1997 relates to forming a supportedtransition metal compound in the presence of an unsaturated organiccompound having at least one terminal double bond; and EP-A2-811 638discusses using a metallocene catalyst and an activating cocatalyst in apolymerization process in the presence of a nitrogen containingantistatic agent.

U.S. Pat. Nos. 4,942,147 and 5,362,823 discuss the addition ofautoacceleration inhibitors to prevent sheeting. WO 00/35969 discussesthe use of an acid and a base with a polymerization catalyst that reactat a certain temperature to form a catalyst poison. WO 00/35967discloses the use of a solid polar compound, whose melting point isabove the normal reactor temperature but below the melting point of thepolymer, which melts without decomposition or a chemical transformationand poisons the catalyst should overheating occur. While all thesepossible solutions might reduce the level of fouling or sheetingsomewhat, some are expensive to employ and/or may not reduce fouling andsheeting to a level sufficient to successfully operate a continuousprocess, particularly a commercial or large-scale process.

Thus, it would be advantageous to have a polymerization process capableof operating continuously with enhanced reactor operability and at thesame time produce new and improved polymers. It would also be highlybeneficial to have a continuously operating polymerization processhaving more stable catalyst productivities, reduced fouling/sheetingtendencies and increased duration of operation.

SUMMARY OF THE INVENTION

This invention provides a method of making a new and improved catalystcomposition, the catalyst composition itself and its use in apolymerizing process. Also, the invention is directed to the use of athermally triggered compound that in the presence of a polymerizationcatalyst reacts at a specified temperature during a polymerizationprocess to release at least one compound that is a catalyst inhibitor,either a gas or a liquid, preferably a gas. The most preferred thermallytriggered compounds are solid beta-keto acids, specifically a beta-ketocarboxylic acid that melts between about 80° C. to about 120° C. and hasa weight loss of greater than or equal to 5 weight percent at about 110°C. to less than or equal to 0.02 weight percent at about 80° C. using astandard thermogravimetric analysis (TGA) at 80° C. or 110° C. for 20minutes.

The method for preparing the catalyst composition comprises the step ofcombining, contacting, blending and/or mixing any catalyst system,preferably a supported catalyst system, with the thermally triggeredcompound such that at a specified temperature the thermally triggeredcompound reacts to form at least one catalyst inhibitor, preferably twocatalyst inhibitors both of which are either gasses or liquids,preferably at least one is a gas and at least one is a liquid, thatdeactivates the catalyst composition. In the most preferred embodiment,the solid, thermally triggered compounds react at a temperature abovethe polymerization temperature, reactor temperature, to form the two ormore catalyst inhibitors, more preferably a gaseous catalyst inhibitorand a liquid catalyst inhibitor. In one embodiment, the catalyst systemcomprises a conventional-type transition metal catalyst compound. In themost preferred embodiment the catalyst composition comprises a bulkyligand metallocene catalyst compound. The combination or use of anolefin polymerization catalyst and a thermally triggered compound isuseful in any olefin polymerization process. The preferredpolymerization processes are a gas phase or a slurry phase process, mostpreferably a gas phase process.

In another preferred embodiment, the invention provides for a processfor polymerizing olefin(s) in the presence of a polymerization catalystand a thermally triggered compound in a reactor at an operatingtemperature, wherein the thermally triggered compound chemically changesor transforms at a temperature above the operating temperature to format least one catalyst inhibitor, preferably at least two catalystinhibitors that reduce the effectiveness of the polymerization catalystto polymerize olefin(s). In the most preferred embodiment, the catalystinhibitors render the polymerization catalyst inactive and the catalystinhibitors comprise a gaseous catalyst inhibitor and a liquid catalystinhibitor.

DETAILED DESCRIPTION OF THE INVENTION

Introduction

The invention is directed toward a method for making a catalystcomposition and to the catalyst composition itself. The invention alsorelates to a polymerization process having improved operability usingthe catalyst composition. While not being bound to any particulartheory, it is believed that one possible cause for reduced operability,especially sheeting and/or fouling, is the result of a catalyst'stendency to continue to polymerize well after its initial activation. Ithas been suprisingly discovered that using a thermally triggeredcompound that chemical transforms into one or more catalyst inhibitors,preferably two catalyst inhibitors, one gas and one liquid, incombination with a polymerization catalyst, results in the ability tocontrol the catalyst's tendency for continuing to effectively polymerizeolefin(s). It has also been discovered that the chemical transformationforming the catalyst inhibitors is controllable. For example, thethermally triggered compound will essentially remain unchanged duringnormal operating temperatures, but as soon as catalyst particle becomesoverheated, the compound transforms into one or more catalyst inhibitorsthat kills the polymerization catalyst fairly quickly. Without beingbound to any particular theory, it is believed that this may mean thatthe thermally triggered compounds must have a high activation energyE_(a) for the reaction of the catalyst inhibitors to the overheatedpolymerization catalyst, especially for achieving a particulartemperature sensitivity. However, a high E_(a) typically tends toward aslower rate of reaction, thus more of the thermally triggered compoundis required. Surprisingly, the thermally triggered compounds of thepresent invention provide both a high Ea and a fast rate. It would bewithin the skill in the art using the Arrhenius equation to predictthermally triggered compounds for use at a particular temperature range.The present invention is useful in all types of polymerizationprocesses, especially a slurry or gas phase process.

Catalyst Components and Catalyst Systems

All polymerization catalysts including conventional-type transitionmetal catalysts and bulky ligand metallocene catalysts are suitable foruse in the polymerizing process of the invention. The following is anon-limiting discussion of the various polymerization catalysts usefulin the invention.

Conventional-type Transition Metal Catalysts

Conventional-type transition metal catalysts are those traditionalZiegler-Natta catalysts and Phillips-type catalysts well known in theart. Examples of conventional-type transition metal catalysts arediscussed in U.S. Pat. Nos. 4,115,639, 4,077,904, 4,482,687, 4,564,605,4,721,763, 4,879,359 and 4,960,741 all of which are herein fullyincorporated by reference. The conventional-type transition metalcatalyst compounds that may be used in the present invention includetransition metal compounds from Groups 3 to 17, preferably 4 to 12, morepreferably 4 to 6 of the Periodic Table of Elements.

These conventional-type transition metal catalysts may be represented bythe formula: MR_(x), where M is a metal from Groups 3 to 17, preferablyGroup 4 to 6, more preferably Group 4, most preferably titanium; R is ahalogen or a hydrocarbyloxy group; and x is the valence of the metal M.Non-limiting examples of R include alkoxy, phenoxy, bromide, chlorideand fluoride. Non-limiting examples of conventional-type transitionmetal catalysts where M is titanium include TiCl₄, TiBr₄, Ti(OC₂H₅)₃Cl,Ti(OC₂H₅)Cl₃, Ti(OC₄H₅)₃Cl, Ti(OC₃H₇)₂Cl₂, Ti(OC₂H₅)₂Br₂, TiCl₃.1/3AlCl₃and Ti(OC₁₂H₂₅)Cl₃.

Conventional-type transition metal catalyst compounds based onmagnesium/titanium electron-donor complexes that are useful in theinvention are described in, for example, U.S. Pat. Nos. 4,302,565 and4,302,566, which are herein fully incorporate by reference. The MgTiCl₆(ethyl acetate)₄ derivative is particularly preferred.

British Pat. Application 2,105,355 and U.S. Pat. No. 5,317,036, hereinincorporated by reference, describes various conventional-type vanadiumcatalyst compounds. Non-limiting examples of conventional-type vanadiumcatalyst compounds include vanadyl trihalide, alkoxy halides andalkoxides such as VOCl₃, VOCl₂(OBu) where Bu=butyl and VO(OC₂H₅)₃;vanadium tetra-halide and vanadium alkoxy halides such as VCl₄ andVCl₃(OBu); vanadium and vanadyl acetyl acetonates and chloroacetylacetonates such as V(AcAc)₃ and VOCl₂(AcAc) where (AcAc) is an acetylacetonate. The preferred conventional-type vanadium catalyst compoundsare VOCl₃, VCl₄ and VOCl₂—OR where R is a hydrocarbon radical,preferably a C₁ to C₁₀ aliphatic or aromatic hydrocarbon radical such asethyl, phenyl, isopropyl, butyl, propyl, n-butyl, iso-butyl,tertiary-butyl, hexyl, cyclohexyl, naphthyl, etc., and vanadium acetylacetonates.

Conventional-type chromium catalyst compounds, often referred to asPhillips-type catalysts, suitable for use in the present inventioninclude CrO₃, chromocene, silyl chromate, chromyl chloride (CrO₂Cl₂),chromium-2-ethyl-hexanoate, chromium acetylacetonate (Cr(AcAc)₃), andthe like. Non-limiting examples are disclosed in U.S. Pat. Nos.3,709,853, 3,709,954, 3,231,550, 3,242,099 and 4,077,904, which areherein fully incorporated by reference.

Still other conventional-type transition metal catalyst compounds andcatalyst systems suitable for use in the present invention are disclosedin U.S. Pat. Nos. 4,124,532, 4,302,565, 4,302,566, 4,376,062, 4,379,758,5,066,737, 5,763,723, 5,849,655, 5,852,144, 5,854,164 and 5,869,585 andpublished EP-A2 0 416 815 A2 and EP-A1 0 420 436, which are all hereinincorporated by reference.

Other catalysts may include cationic catalysts such as AlCl₃, and othercobalt, iron, nickel and palladium catalysts well known in the art. Seefor example U.S. Pat. Nos. 3,487,112, 4,472,559, 4,182,814 and 4,689,437all of which are incorporated herein by reference.

Typically, these conventional-type transition metal catalyst compoundsexcluding some conventional-type chromium catalyst compounds areactivated with one or more of the conventional-type cocatalystsdescribed below.

Conventional-type Cocatalysts

Conventional-type cocatalyst compounds for the above conventional-typetransition metal catalyst compounds may be represented by the formulaM³M⁴ _(v)X² _(c)R³ _(b-c), wherein M³ is a metal from Group 1 to 3 and12 to 13 of the Periodic Table of Elements; M⁴ is a metal of Group 1 ofthe Periodic Table of Elements; v is a number from 0 to 1; each X² isany halogen; c is a number from 0 to 3; each R³ is a monovalenthydrocarbon radical or hydrogen; b is a number from 1 to 4; and whereinb minus c is at least 1. Other conventional-type organometalliccocatalyst compounds for the above conventional-type transition metalcatalysts have the formula M³R³ _(k), where M³ is a Group IA, IIA, IIBor IIIA metal, such as lithium, sodium, beryllium, barium, boron,aluminum, zinc, cadmium, and gallium; k equals 1, 2 or 3 depending uponthe valency of M³ which valency in turn normally depends upon theparticular Group to which M³ belongs; and each R³ may be any monovalentradical that include hydrocarbon radicals and hydrocarbon radicalscontaining a Group 13 to 16 element like fluoride, aluminum or oxygen ora combination thereof.

Non-limiting examples of conventional-type organometallic cocatalystcompounds useful with the conventional-type catalyst compounds describedabove include methyllithium, butyllithium, dihexylmercury,butylmagnesium, diethylcadmium, benzylpotassium, diethylzinc,tri-n-butylaluminum, diisobutyl ethylboron, diethylcadmium,di-n-butylzinc and tri-n-amylboron, and, in particular, the aluminumalkyls, such as tri-hexyl-aluminum, triethylaluminum, trimethylaluminum,and tri-isobutylaluminum. Other conventional-type cocatalyst compoundsinclude mono-organohalides and hydrides of Group 2 metals, and mono- ordi-organohalides and hydrides of Group 3 and 13 metals. Non-limitingexamples of such conventional-type cocatalyst compounds includedi-isobutylaluminum bromide, isobutylboron dichloride, methyl magnesiumchloride, ethylberyllium chloride, ethylcalcium bromide,di-isobutylaluminum hydride, methylcadmium hydride, diethylboronhydride, hexylberyllium hydride, dipropylboron hydride, octylmagnesiumhydride, butylzinc hydride, dichloroboron hydride, di-bromo-aluminumhydride and bromocadmium hydride. Conventional-type organometalliccocatalyst compounds are known to those in the art and a more completediscussion of these compounds may be found in U.S. Pat. Nos. 3,221,002and 5,093,415, which are herein fully incorporated by reference.

Bulky Ligand Metallocene Catalyst Compounds

Generally, bulky ligand metallocene catalyst compounds include half andfull sandwich compounds having one or more bulky ligands bonded to atleast one metal atom. Typical bulky ligand metallocene compounds aregenerally described as containing one or more bulky ligand(s) and one ormore leaving group(s) bonded to at least one metal atom. In onepreferred embodiment, at least one bulky ligands is η-bonded to themetal atom, most preferably η⁵-bonded to the metal atom.

The bulky ligands are generally represented by one or more open,acyclic, or fused ring(s) or ring system(s) or a combination thereof.These bulky ligands, preferably the ring(s) or ring system(s), aretypically composed of atoms selected from Groups 13 to 16 atoms of thePeriodic Table of Elements, preferably the atoms are selected from thegroup consisting of carbon, nitrogen, oxygen, silicon, sulfur,phosphorous, germanium, boron and aluminum or a combination thereof.Most preferably the ring(s) or ring system(s) are composed of carbonatoms such as but not limited to those cyclopentadienyl ligands orcyclopentadienyl-type ligand structures or other similar functioningligand structure such as a pentadiene, a cyclooctatetraendiyl or animide ligand. The metal atom is preferably selected from Groups 3through 15 and the lanthanide or actinide series of the Periodic Tableof Elements. Preferably the metal is a transition metal from Groups 4through 12, more preferably Groups 4, 5 and 6, and most preferably thetransition metal is from Group 4.

In one embodiment, the bulky ligand metallocene catalyst compounds ofthe invention are represented by the formula:

L^(A)L^(B)MQ_(n)  (I)

where M is a metal atom from the Periodic Table of the Elements and maybe a Group 3 to 12 metal or from the lanthanide or actinide series ofthe Periodic Table of Elements, preferably M is a Group 4, 5 or 6transition metal, more preferably M is a Group 4 transition metal, evenmore preferably M is zirconium, hafnium or titanium. The bulky ligands,L^(A) and L^(B), are open, acyclic or fused ring(s) or ring system(s)such as unsubstituted or substituted, cyclopentadienyl ligands orcyclopentadienyl-type ligands, heteroatom substituted and/or heteroatomcontaining cyclopentadienyl-type ligands. Non-limiting examples of bulkyligands include cyclopentadienyl ligands, cyclopentaphenanthreneylligands, indenyl ligands, benzindenyl ligands, fluorenyl ligands,octahydrofluorenyl ligands, cyclooctatetraendiyl ligands, azenylligands, azulene ligands, pentalene ligands, phosphoyl ligands, pyrrolylligands, pyrozolyl ligands, carbazolyl ligands, borabenzene ligands andthe like, including hydrogenated versions thereof, for exampletetrahydroindenyl ligands. In one embodiment, L^(A) and L^(B) may be anyother ligand structure capable of η-bonding to M, preferably η³-bondingto M and most preferably η⁵-bonding. In yet another embodiment, theatomic molecular weight (MW) of L^(A) or L^(B) exceeds 60 a.m.u.,preferably greater than 65 a.m.u. In another embodiment, L^(A) and L^(B)may comprise one or more heteroatoms, for example, nitrogen, silicon,boron, germanium, sulfur, oxygen and phosphorous, in combination withcarbon atoms to form an open, acyclic, or preferably a fused, ring orring system, for example, a hetero-cyclopentadienyl ancillary ligand.Other L^(A) and L^(B) bulky ligands include but are not limited to bulkyamides, phosphides, alkoxides, aryloxides, imides, carbolides,borollides, porphyrins, phthalocyanines, corrins and otherpolyazomacrocycles. Independently, each L^(A) and L^(B) may be the sameor different type of bulky ligand that is bonded to M. In one embodimentof formula (I) only one of either L^(A) or L^(B) is present.

Independently, each L^(A) and L^(B) may be unsubstituted or substitutedwith a combination of substituent groups R. Non-limiting examples ofsubstituent groups R include one or more from the group selected fromhydrogen, or linear, branched alkyl radicals, or alkenyl radicals,alkynyl radicals, cycloalkyl radicals or aryl radicals, acyl radicals,aroyl radicals, alkoxy radicals, aryloxy radicals, alkylthio radicals,dialkylamino radicals, alkoxycarbonyl radicals, aryloxycarbonylradicals, carbomoyl radicals, alkyl- or dialkyl-carbamoyl radicals,acyloxy radicals, acylamino radicals, aroylamino radicals, straight,branched or cyclic, alkylene radicals, or combination thereof. In apreferred embodiment, substituent groups R have up to 50 non-hydrogenatoms, preferably from 1 to 30 carbon, that can also be substituted withhalogens or heteroatoms or the like. Non-limiting examples of alkylsubstituents R include methyl, ethyl, propyl, butyl, pentyl, hexyl,cyclopentyl, cyclohexyl, benzyl or phenyl groups and the like, includingall their isomers, for example tertiary butyl, isopropyl, and the like.Other hydrocarbyl radicals include fluoromethyl, fluroethyl,difluroethyl, iodopropyl, bromohexyl, chlorobenzyl and hydrocarbylsubstituted organometalloid radicals including trimethylsilyl,trimethylgermyl, methyldiethylsilyl and the like; andhalocarbyl-substituted organometalloid radicals includingtris(trifluoromethyl)-silyl, methyl-bis(difluoromethyl)silyl,bromomethyldimethylgermyl and the like; and disubstitiuted boronradicals including dimethylboron for example; and disubstitutedpnictogen radicals including dimethylamine, dimethylphosphine,diphenylamine, methylphenylphosphine, chalcogen radicals includingmethoxy, ethoxy, propoxy, phenoxy, methylsulfide and ethylsulfide.Non-hydrogen substituents R include the atoms carbon, silicon, boron,aluminum, nitrogen, phosphorous, oxygen, tin, sulfur, germanium and thelike, including olefins such as but not limited to olefinicallyunsaturated substituents including vinyl-terminated ligands, for examplebut-3-enyl, prop-2-enyl, hex-5-enyl and the like. Also, at least two Rgroups, preferably two adjacent R groups, are joined to form a ringstructure having from 3 to 30 atoms selected from carbon, nitrogen,oxygen, phosphorous, silicon, germanium, aluminum, boron or acombination thereof. Also, a substituent group R group such as 1-butanylmay form a carbon sigma bond to the metal M.

Other ligands may be bonded to the metal M, such as at least one leavinggroup Q. For the purposes of this patent specification and appendedclaims the term “leaving group” is any ligand that can be abstractedfrom a bulky ligand metallocene catalyst compound to form a bulky ligandmetallocene catalyst cation capable of polymerizing one or moreolefin(s). In one embodiment, Q is a monoanionic labile ligand having asigma-bond to M.

Non-limiting examples of Q ligands include weak bases such as amines,phosphines, ethers, carboxylates, dienes, hydrocarbyl radicals havingfrom 1 to 20 carbon atoms, hydrides or halogens and the like or acombination thereof. In another embodiment, two or more Q's form a partof a fused ring or ring system. Other examples of Q ligands includethose substituents for R as described above and including cyclobutyl,cyclohexyl, heptyl, tolyl, trifluromethyl, tetramethylene,pentamethylene, methylidene, methyoxy, ethyoxy, propoxy, phenoxy,bis(N-methylanilide), dimethylamide, dimethylphosphide radicals and thelike. Depending on the oxidation state of the metal, the value for n is0, 1 or 2 such that formula (I) above represents a neutral bulky ligandmetallocene catalyst compound.

In one embodiment, the bulky ligand metallocene catalyst compounds ofthe invention include those of formula (I) where L^(A) and L^(B) arebridged to each other by a bridging group, A, such that the formula isrepresented by

L^(A)AL^(B)MQ_(n)  (II)

These bridged compounds represented by formula (II) are known asbridged, bulky ligand metallocene catalyst compounds. L^(A), L^(B), M, Qand n are as defined above. Non-limiting examples of bridging group Ainclude bridging groups containing at least one Group 13 to 16 atom,often referred to as a divalent moiety such as but not limited to atleast one of a carbon, oxygen, nitrogen, silicon, boron, germanium andtin atom or a combination thereof. Preferably bridging group A containsa carbon, silicon, iron or germanium atom, most preferably A contains atleast one silicon atom or at least one carbon atom. The bridging group Amay also contain substituent groups R as defined above includinghalogens. Non-limiting examples of bridging group A may be representedby R′₂C, R′₂Si, R′₂Si R′₂Si, R′₂Ge, R′P, where R′ is independently, aradical group which is hydride, hydrocarbyl, substituted hydrocarbyl,halocarbyl, substituted halocarbyl, hydrocarbyl-substitutedorganometalloid, halocarbyl-substituted organometalloid, disubstitutedboron, disubstituted pnictogen, substituted chalcogen, or halogen or twoor more R′ may be joined to form a ring or ring system.

In one embodiment, the bulky ligand metallocene catalyst compounds arethose where the R substituents on the bulky ligands L^(A) and L^(B) offormulas (I) and (II) are substituted with the same or different numberof substituents on each of the bulky ligands. In another embodiment, thebulky ligands L^(A) and L^(B) of formulas (I) and (II) are differentfrom each other.

Other bulky ligand metallocene catalyst compounds and catalyst systemsuseful in the invention may include those described in U.S. Pat. Nos.5,064,802, 5,145,819, 5,149,819, 5,243,001, 5,239,022, 5,276,208,5,296,434, 5,321,106, 5,329,031, 5,304,614, 5,677,401, 5,723,398,5,753,578, 5,854,363 and 5,856,547 5,858,903, 5,859,158 and 5,929,266and PCT publications WO 93/08221, WO 93/08199, WO 95/07140, WO 98/11144,WO 98/41530, WO 98/41529, WO 98/46650, WO 99/02540 and WO 99/14221 andEuropean publications EP-A-0 578 838, EP-A-0 638 595, EP-B-0 513 380,EP-A1-0 816 372, EP-A2-0 839 834, EP-B1-0 632 819, EP-B1-0 748 821 andEP-B1-0 757 996, all of which are herein fully incorporated byreference.

In one embodiment, bulky ligand metallocene catalysts compounds usefulin the invention include bridged heteroatom, mono-bulky ligandmetallocene compounds. These types of catalysts and catalyst systems aredescribed in, for example, PCT publication WO 92/00333, WO 94/07928, WO91/04257, WO 94/03506, WO96/00244 and WO 97/15602 and U.S. Pat. Nos.5,057,475, 5,096,867, 5,055,438, 5,198,401, 5,227,440 and 5,264,405 andEuropean publication EP-A-0 420 436, all of which are herein fullyincorporated by reference.

In this embodiment, the bulky ligand metallocene catalyst compound isrepresented by the formula:

L^(c)AJMQ_(n)  (III)

where M is a Group 3 to 16 metal atom or a metal selected from the Groupof actinides and lanthanides of the Periodic Table of Elements,preferably M is a Group 4 to 12 transition metal, and more preferably Mis a Group 4, 5 or 6 transition metal, and most preferably M is a Group4 transition metal in any oxidation state, especially titanium; L^(c) isa substituted or unsubstituted bulky ligand bonded to M; J is bonded toM; A is bonded to L^(c) and J; J is a heteroatom ancillary ligand; and Ais a bridging group; Q is a univalent anionic ligand; and n is theinteger 0,1 or 2. In formula (III) above, L_(c), A and J form a fusedring system. In an embodiment, L^(c) of formula (III) is as definedabove for L^(A), A, M and Q of formula (III) are as defined above informula (I). In formula (III) J is a heteroatom containing ligand inwhich J is an element with a coordination number of three from Group 15or an element with a coordination number of two from Group 16 of thePeriodic Table of Elements. Preferably J contains a nitrogen,phosphorus, oxygen or sulfur atom with nitrogen being most preferred.

In another embodiment, the bulky ligand type metallocene catalystcompound is a complex of a metal, preferably a transition metal, a bulkyligand, preferably a substituted or unsubstituted pi-bonded ligand, andone or more heteroallyl moieties, such as those described in U.S. Pat.Nos. 5,527,752 and 5,747,406 and EP-B1-0 735 057, all of which areherein fully incorporated by reference.

In an embodiment, the bulky ligand metallocene catalyst compound isrepresented by the formula:

L^(D)MQ₂(YZ)X_(n)  (IV)

where M is a Group 3 to 16 metal, preferably a Group 4 to 12 transitionmetal, and most preferably a Group 4, 5 or 6 transition metal; L^(D) isa bulky ligand that is bonded to M; each Q is independently bonded to Mand Q₂(YZ) forms a unicharged polydentate ligand; A or Q is a univalentanionic ligand also bonded to M; X is a univalent anionic group when nis 2 or X is a divalent anionic group when n is 1; n is 1 or 2.

In formula (IV), L and M are as defined above for formula (I). Q is asdefined above for formula (I), preferably Q is selected from the groupconsisting of —O—, —NR—, —CR₂— and —S—; Y is either C or S; Z isselected from the group consisting of —OR, —NR₂, —CR₃, —SR, —SiR₃, —PR₂,—H, and substituted or unsubstituted aryl groups, with the proviso thatwhen Q is —NR— then Z is selected from one of the group consisting of—OR, —NR₂, —SR, —SiR₃, —PR₂ and —H; R is selected from a groupcontaining carbon, silicon, nitrogen, oxygen, and/or phosphorus,preferably where R is a hydrocarbon group containing from 1 to 20 carbonatoms, most preferably an alkyl, cycloalkyl, or an aryl group; n is aninteger from 1 to 4, preferably 1 or 2; X is a univalent anionic groupwhen n is 2 or X is a divalent anionic group when n is 1; preferably Xis a carbamate, carboxylate, or other heteroallyl moiety described bythe Q, Y and Z combination.

In another embodiment of the invention, the bulky ligandmetallocene-type catalyst compounds are heterocyclic ligand complexeswhere the bulky ligands, the ring(s) or ring system(s), include one ormore heteroatoms or a combination thereof. Non-limiting examples ofheteroatoms include a Group 13 to 16 element, preferably nitrogen,boron, sulfur, oxygen, aluminum, silicon, phosphorous and tin. Examplesof these bulky ligand metallocene catalyst compounds are described in WO96/33202, WO 96/34021, WO 97/17379 and WO 98/22486 and EP-AL-0 874 005and U.S. Pat. Nos. 5,637,660, 5,539,124, 5,554,775, 5,756,611,5,233,049, 5,744,417, and 5,856,258 all of which are herein incorporatedby reference.

In another embodiment, the bulky ligand metallocene catalyst compoundsare those complexes known as transition metal catalysts based onbidentate ligands containing pyridine or quinoline moieties, such asthose described in U.S. application Ser. No. 09/103,620 filed Jun. 23,1998, which is herein incorporated by reference. In another embodiment,the bulky ligand metallocene catalyst compounds are those described inPCT publications WO 99/01481 and WO 98/42664, which are fullyincorporated herein by reference.

In one embodiment, the bulky ligand metallocene catalyst compound isrepresented by the formula:

((Z)XA_(t)(YJ))_(q)MQ_(n)  (V)

where M is a metal selected from Group 3 to 13 or lanthanide andactinide series of the Periodic Table of Elements; Q is bonded to M andeach Q is a monovalent, bivalent, or trivalent anion; X and Y are bondedto M; one or more of X and Y are heteroatoms, preferably both X and Yare heteroatoms; Y is contained in a heterocyclic ring J, where Jcomprises from 2 to 50 non-hydrogen atoms, preferably 2 to 30 carbonatoms; Z is bonded to X, where Z comprises 1 to 50 non-hydrogen atoms,preferably 1 to 50 carbon atoms, preferably Z is a cyclic groupcontaining 3 to 50 atoms, preferably 3 to 30 carbon atoms; t is 0 or 1;when t is 1, A is a bridging group joined to at least one of X,Y or J,preferably X and J; q is 1 or 2; n is an integer from 1 to 4 dependingon the oxidation state of M. In one embodiment, where X is oxygen orsulfur then Z is optional. In another embodiment, where X is nitrogen orphosphorous then Z is present. In an embodiment, Z is preferably an arylgroup, more preferably a substituted aryl group.

Other Bulky Ligand Metallocene Catalyst Compounds

It is within the scope of this invention, in one embodiment, that thebulky ligand metallocene catalyst compounds include complexes of Ni²⁺and Pd²⁺ described in the articles Johnson, et al., “New Pd(II)- andNi(II)-Based Catalysts for Polymerization of Ethylene and a-Olefins”, J.Am. Chem. Soc. 1995, 117, 6414-6415 and Johnson, et al.,“Copolymerization of Ethylene and Propylene with Functionalized VinylMonomers by Palladium(II) Catalysts”, J. Am. Chem. Soc., 1996, 118,267-268, and WO 96/23010 published Aug. 1, 1996, WO 99/02472, U.S. Pat.Nos. 5,852,145, 5,866,663 and 5,880,241, which are all herein fullyincorporated by reference. These complexes can be either dialkyl etheradducts, or alkylated reaction products of the described dihalidecomplexes that can be activated to a cationic state by the activators ofthis invention described below.

Also included as bulky ligand metallocene catalyst are those diiminebased ligands of Group 8 to 10 metal compounds disclosed in PCTpublications WO 96/23010 and WO 97/48735 and Gibson, et. al., Chem.Comm., pp. 849-850 (1998), all of which are herein incorporated byreference.

Other bulky ligand metallocene catalysts are those Group 5 and 6 metalimido complexes described in EP-A2-0 816 384 and U.S. Pat. No.5,851,945, which is incorporated herein by reference. In addition, bulkyligand metallocene catalysts include bridged bis(arylamido) Group 4compounds described by D. H. McConville, et al., in Organometallics1195, 14, 5478-5480, which is herein incorporated by reference. Otherbulky ligand metallocene catalysts are described as bis(hydroxy aromaticnitrogen ligands) in U.S. Pat. No. 5,852,146, which is incorporatedherein by reference. Other metallocene catalysts containing one or moreGroup 15 atoms include those described in WO 98/46651, which is hereinincorporated herein by reference.

It is also contemplated that in one embodiment, the bulky ligandmetallocene catalysts of the invention described above include theirstructural or optical or enantiomeric isomers (meso and racemic isomers,for example see U.S. Pat. No. 5,852,143, incorporated herein byreference) and mixtures thereof.

Activator and Activation Methods for the Bulky Ligand MetalloceneCatalyst Compounds

The above described bulky ligand metallocene catalyst compounds aretypically activated in various ways to yield catalyst compounds having avacant coordination site that will coordinate, insert, and polymerizeolefin(s), an activated polymerization catalyst.

For the purposes of this patent specification and appended claims, theterm “activator” is defined to be any compound or component or methodwhich can activate any of the bulky ligand metallocene catalystcompounds of the invention as described above. Non-limiting activators,for example may include a Bronsted acid or a non-coordinating ionicactivator or ionizing activator or any other compound including Bronstedbases, aluminum alkyls, conventional-type cocatalysts and combinationsthereof that can convert a neutral bulky ligand metallocene catalystcompound to a catalytically active bulky ligand metallocene cation. Itis within the scope of this invention to use alumoxane or modifiedalumoxane as an activator, and/or to also use ionizing activators,neutral or ionic, such as tri (n-butyl) ammonium tetrakis(pentafluorophenyl) boron, a trisperfluorophenyl boron metalloidprecursor or a trisperfluoronaphtyl boron metalloid precursor,polyhalogenated heteroborane anions (WO 98/43983) or combinationthereof, that would ionize the neutral bulky ligand metallocene catalystcompound.

In one embodiment, an activation method using ionizing ionic compoundsnot containing an active proton but capable of producing both a bulkyligand metallocene catalyst cation and a non-coordinating anion are alsocontemplated, and are described in EP-A-0 426 637, EP-A-0 573 403 andU.S. Pat. No. 5,387,568, which are all herein incorporated by reference.

There are a variety of methods for preparing alumoxane and modifiedalumoxanes, non-limiting examples of which are described in U.S. Pat.Nos. 4,665,208, 4,952,540, 5,091,352, 5,206,199, 5,204,419, 4,874,734,4,924,018, 4,908,463, 4,968,827, 5,308,815, 5,329,032, 5,248,801,5,235,081, 5,157,137, 5,103,031, 5,391,793, 5,391,529, 5,693,838,5,731,253, 5,731,451, 5,744,656, 5,847,177, 5,854,166 and 5,856,256 andEuropean publications EP-A-0 561 476, EP-B1-0 279 586, EP-A-0 594-218and EP-B1-0 586 665, and PCT publication WO 94/10180, all of which areherein fully incorporated by reference.

Organoaluminum compounds useful as activators include triethylaluminum,triisobutylaluminum, trimethylaluminum, tri-n-hexyl aluminum and thelike.

Ionizing compounds may contain an active proton, or some other cationassociated with but not coordinated to or only loosely coordinated tothe remaining ion of the ionizing compound. Such compounds and the likeare described in European publications EP-A-0 570 982, EP-A-0 520 732,EP-A-0 495 375, EP-B 1-0 500 944, EP-A-0 277 003 and EP-A-0 277 004, andU.S. Pat. Nos. 5,153,157, 5,198,401, 5,066,741, 5,206,197, 5,241,025,5,384,299 and 5,502,124 and U.S. patent application Ser. No. 08/285,380,filed Aug. 3, 1994, all of which are herein fully incorporated byreference.

Other activators include those described in PCT publication WO 98/07515such as tris (2,2′, 2″-nonafluorobiphenyl) fluoroaluminate, whichpublication is fully incorporated herein by reference. Combinations ofactivators are also contemplated by the invention, for example,alumoxanes and ionizing activators in combinations, see for example,EP-B1 0 573 120, PCT publications WO 94/07928 and WO 95/14044 and U.S.Pat. Nos. 5,153,157 and 5,453,410 all of which are herein fullyincorporated by reference. Other activators include aluminum/boroncomplexes as described in EP 608 830 B1, which is herein incorporated byreference. WO 98/09996 incorporated herein by reference describesactivating bulky ligand metallocene catalyst compounds withperchlorates, periodates and iodates including their hydrates. WO98/30602 and WO 98/30603 incorporated by reference describe the use oflithium (2,2′-bisphenyl-ditrimethylsilicate).4THF as an activator for abulky ligand metallocene catalyst compound. EP-B 1-0 781 299 describesusing a silylium salt in combination with a non-coordinating compatibleanion. Also, methods of activation such as using radiation (see EP-B 1-0615 981 herein incorporated by reference), electrochemical oxidation,and the like are also contemplated as activating methods for thepurposes of rendering the neutral bulky ligand metallocene catalystcompound or precursor to a bulky ligand metallocene cation capable ofpolymerizing olefins. Other activators or methods for activating a bulkyligand metallocene catalyst compound are described in for example, U.S.Pat. Nos. 5,849,852, 5,859,653 and 5,869,723 and PCT WO 98/32775, whichare herein incorporated by reference.

It is also within the scope of this invention that the above describedbulky ligand metallocene catalyst compounds can be combined with one ormore of the catalyst compounds represented by formulas (I) through (V)with one or more activators or activation methods described above.

It is further contemplated by the invention that other catalysts can becombined with the bulky ligand metallocene catalyst compounds of theinvention. For example, see U.S. Pat. Nos. 4,937,299, 4,935,474,5,281,679, 5,359,015, 5,470,811, and 5,719,241 all of which are hereinfully incorporated herein reference. It is also contemplated that anyone of the bulky ligand metallocene catalyst compounds of the inventionhave at least one fluoride or fluorine containing leaving group asdescribed in U.S. application Ser. No. 09/191,916 filed Nov. 13, 1998.

In another embodiment of the invention one or more bulky ligandmetallocene catalyst compounds or catalyst systems may be used incombination with one or more conventional-type catalyst compounds orcatalyst systems. Non-limiting examples of mixed catalysts and catalystsystems are described in U.S. Pat. Nos. 4,159,965, 4,325,837, 4,701,432,5,124,418, 5,077,255, 5,183,867, 5,391,660, 5,395,810, 5,691,264,5,723,399 and 5,767,031 and PCT Publication WO 96/23010 published Aug.1, 1996, all of which are herein fully incorporated by reference.

Supports, Carriers and General Supporting Techniques

The above described conventional-type transition metal catalystcompounds and catalyst systems and bulky ligand metallocene catalystcompounds, activators, cocatalysts and/or catalyst systems may becombined with one or more support materials or carriers using one of thesupport methods well known in the art or as described below. Forexample, in a most preferred embodiment, a bulky ligand metallocenecatalyst compound, an activator or catalyst system is in a supportedform, for example deposited on, contacted with, vapourized with, bondedto, or incorporated within, adsorbed or absorbed in, or on, a support orcarrier.

The terms “support” or “carrier” are used interchangeably and are anysupport material, preferably a porous support material, more preferablyan inorganic support or an organic support. Inorganic supports arepreferred for example inorganic oxides and inorganic chlorides. Othercarriers include resinous support materials such as polystyrene,functionalized or crosslinked organic supports, such as polystyrenedivinyl benzene polyolefins or polymeric compounds, zeolites, clays,talc, or any other organic or inorganic support material and the like,or mixtures thereof. The most preferred carriers are inorganic oxidesthat include those Group 2, 3, 4, 5, 13 or 14 metal oxides. Thepreferred supports include silica, alumina, silica-alumina, magnesiumchloride, and mixtures thereof.

Other useful supports include magnesia, titania, zirconia,montmorillonite (EP-B1 0 511 665) and the like. Also, combinations ofthese support materials may be used, for example, silica-chromium,silica-alumina, silica-titania and the like.

It is preferred that the carrier, most preferably an inorganic oxide,has a surface area in the range of from about 10 to about 700 m²/g, porevolume in the range of from about 0.1 to about 4.0 cc/g and averageparticle size in the range of from about 5 to about 500 μm. Morepreferably, the surface area of the carrier is in the range of fromabout 50 to about 500 m²/g, pore volume of from about 0.5 to about 3.5cc/g and average particle size of from about 10 to about 200 μm. Mostpreferably the surface area of the carrier is in the range is from about100 to about 400 m²/g, pore volume from about 0.8 to about 3.0 cc/g andaverage particle size is from about 5 to about 100 μm. The average poresize of the carrier of the invention typically has pore size in therange of from 10 to 1000 Å, preferably 50 to about 500 Å, and mostpreferably 75 to about 350 Å.

Examples of supporting the bulky ligand metallocene catalyst systems ofthe invention are described in U.S. Pat. Nos. 4,701,432, 4,808,561,4,912,075, 4,925,821, 4,937,217, 5,008,228, 5,238,892, 5,240,894,5,332,706, 5,346,925, 5,422,325, 5,466,649, 5,466,766, 5,468,702,5,529,965, 5,554,704, 5,629,253, 5,639,835, 5,625,015, 5,643,847,5,665,665, 5,698,487, 5,714,424, 5,723,400, 5,723,402, 5,731,261,5,759,940, 5,767,032, 5,770,664 and 5,846,895 and U.S. application Ser.Nos. 271,598 filed Jul. 7, 1994 and 788,736 filed Jan. 23, 1997 and PCTpublications WO 95/32995, WO 95/14044, WO 96/06187 and WO 97/02297, andEP-B1-0 685 494 all of which are herein fully incorporated by reference.Examples of supporting conventional-type transition metal catalystcompounds are also well known in the art.

There are various other methods in the art for supporting apolymerization catalyst compound or catalyst system of the invention.For example, the bulky ligand metallocene catalyst compound of theinvention may contain a polymer bound ligand as described in U.S. Pat.Nos. 5,473,202 and 5,770,755, which is herein fully incorporated byreference; the bulky ligand metallocene catalyst system of the inventionmay be spray dried as described in U.S. Pat. No. 5,648,310, which isherein fully incorporated by reference; the support used with the bulkyligand metallocene catalyst system of the invention is functionalized asdescribed in European publication EP-A-0 802 203, which is herein fullyincorporated by reference, or at least one substituent or leaving groupis selected as described in U.S. Pat. No. 5,688,880, which is hereinfully incorporated by reference.

In a preferred embodiment, the invention provides for a supported bulkyligand metallocene catalyst system that includes an antistatic agent orsurface modifier that is used in the preparation of the supportedcatalyst system as described in PCT publication WO 96/11960, which isherein fully incorporated by reference. The catalyst systems of theinvention can be prepared in the presence of an olefin, for examplehexene-1.

In another embodiment, the bulky ligand metallocene catalyst system canbe combined with a carboxylic acid salt of a metal ester, for examplealuminum carboxylates such as aluminum mono, di- and tri-stearates,aluminum octoates, oleates and cyclohexylbutyrates, as described in U.S.application Ser. No. 09/113,216, filed Jul. 10, 1998.

A preferred method for producing the supported bulky ligand metallocenecatalyst system of the invention is described below and is described inU.S. application Ser. Nos. 265,533, filed Jun. 24, 1994 and 265,532,filed Jun. 24, 1994 and PCT publications WO 96/00245 and WO 96/00243both published Jan. 4, 1996, all of which are herein fully incorporatedby reference. In this preferred method, the bulky ligand metallocenecatalyst compound is slurried in a liquid to form a metallocene solutionand a separate solution is formed containing an activator and a liquid.The liquid may be any compatible solvent or other liquid capable offorming a solution or the like with the bulky ligand metallocenecatalyst compounds and/or activator of the invention. In the mostpreferred embodiment the liquid is a cyclic aliphatic or aromatichydrocarbon, most preferably toluene. The bulky ligand metallocenecatalyst compound and activator solutions are mixed together and addedto a porous support or the porous support is added to the solutions suchthat the total volume of the bulky ligand metallocene catalyst compoundsolution and the activator solution or the bulky ligand metallocenecatalyst compound and activator solution is less than four times thepore volume of the porous support, more preferably less than threetimes, even more preferably less than two times; preferred ranges beingfrom 1.1 times to 3.5 times range and most preferably in the 1.2 to 3times range.

Procedures for measuring the total pore volume of a porous support arewell known in the art. Details of one of these procedures is discussedin Volume 1, Experimental Methods in Catalytic Research (Academic Press,1968) (specifically see pages 67-96). This preferred procedure involvesthe use of a classical BET apparatus for nitrogen absorption. Anothermethod well known in the art is described in Innes, Total Porosity andParticle Density of Fluid Catalysts By Liquid Titration, Vol. 28, No. 3,Analytical Chemistry 332-334 (March, 1956).

The mole ratio of the metal of the activator component to the metal ofthe supported bulky ligand metallocene catalyst compounds are in therange of between 0.3:1 to 1000:1, preferably 20:1 to 800:1, and mostpreferably 50:1 to 500:1. Where the activator is an ionizing activatorsuch as those based on the anion tetrakis(pentafluorophenyl)boron, themole ratio of the metal of the activator component to the metalcomponent of the bulky ligand metallocene catalyst is preferably in therange of between 0.3:1 to 3:1.

In one embodiment of the invention, olefin(s), preferably C₂ to C₃₀olefin(s) or alpha-olefin(s), preferably ethylene or propylene orcombinations thereof are prepolymerized in the presence of theconventional-type transition metal catalyst system and/or a bulky ligandmetallocene catalyst system of the invention prior to the mainpolymerization. The prepolymerization can be carried out batchwise orcontinuously in gas, solution or slurry phase including at elevatedpressures. The prepolymerization can take place with any olefin monomeror combination and/or in the presence of any molecular weightcontrolling agent such as hydrogen. For examples of prepolymerizationprocedures, see U.S. Pat. Nos. 4,748,221, 4,789,359, 4,923,833,4,921,825, 5,283,278 and 5,705,578 and European publication EP-B-0279863 and PCT Publication WO 97/44371 all of which are herein fullyincorporated by reference. In this embodiment, the prepolymerization iseither in the presence of the thermally triggered compound that is addedafter the prepolymerization, but prior to the main polymerization, orsimply added to the reactor with a already formed prepolymerizedcatalyst or a combination thereof. For the purposes of this patentspecification and appended claims only, prepolymerization is considereda method for immobilizing a catalyst system and therefore considered toform a supported catalyst system.

Compound Combinations

There are various compounds that can be used to form a catalystinhibitor to control the kinetics of an olefin polymerization catalyst.In the preferred embodiment, the invention relates to the use athermally triggered compound in the presence of a polymerizationcatalyst that chemically changes at a specified temperature during apolymerization process to release one or more catalyst inhibitors,preferably one gas and one liquid catalyst inhibitors. In oneembodiment, the triggered compound has a weight loss under standardoperating conditions of no greater than 10 weight percent, preferablyless than 1 weight percent, more preferably less than 0.1 weightpercent, even more preferably less than 0.05 weight percent and mostpreferably less than 0.01 weight percent measured using a standardthermogravimetric analysis (TGA) at 80° C. for 20 minutes.

Yet at higher temperatures, substantial weight loss is observed, due todecomposition of the thermally triggered compound. The rate of weightloss at 130° C. must be at least 10 times as high as at 80° C.,preferably at least 100 times as high, more preferably at least 250times as high, and even more preferably at least 500 times as high, andmost preferably at least 1000 times as high. In another embodiment ofthe invention the solid thermally triggered compound has a meltingtemperature in the range of from 0° C. to 200° C., preferably from 10°C. to 180° C., more preferably from 40° C. to 150° C., and mostpreferably from 80° C. to 130° C. The most preferred thermally triggeredcompounds release gaseous or substantially volatile catalyst inhibitorsthat poison the catalyst. Non-limiting examples of common volatile orgaseous catalyst inhibitors include carbon monoxide, carbon dioxide,water, ammonia, methanol, formaldehyde, acetone, dimethyl ether,cyclopentadiene and formic acid. Non-limiting examples of liquidcatalyst inhibitors include ketones, aldehydes, alcohols, amines,carboxylic acids and esters.

In one embodiment two or more of the gaseous or liquid catalystinhibitors or a combination thereof are chemically formed from a singlethermally triggered compound.

Non-limiting examples of thermally triggered compounds include beta-ketocarboxylic acids, Diels-Alder adducts, metal carbonyl complexes, metalcarbonates, hydrate complexes, clathrate complexes, peroxides,percarboxylic acids, azo compounds, diazonium complexes and sulfones.Identification of potential candidates is easily achieved by scanningcommon repositories of chemical information, such as Beilstein, forexample melting point information. Decomposition on melting, if itoccurs, is usually indicated. By decomposition it is meant that thethermally triggered compound undergoes a chemical change.

In one embodiment, the thermally triggered compound has a melting pointin the range of from 50° C. to about 130° C., preferably in the range offrom about 60° C. to about 120° C., more preferably in the range of from70° C. to about 110° C., and most preferably in the range of from 80° C.to about 105° C.

In another embodiment, the thermally triggered compound has a meltingpoint greater than 60° C., preferably greater than 70° C., morepreferably greater than 75° C., and most preferably greater than 80° C.

In an embodiment, the thermally triggered compound are solids in thetemperature range of from 25° C. to normal reaction conditions oftemperature in the reactor during polymerization. Normal polymerizationtemperatures vary depending on the process used and/or the polymerproduced. Typically polymerization temperatures in a gas phase processare in the range of 50° C. to about 120° C., more preferably from about60° C. to about 110° C., most preferably from about 65° C. to about 100°C. Other polymerization temperatures are discussed later in this patentspecification. In addition, in one embodiment, the thermally triggeredcompounds chemically transform into at least one, preferably two or morecatalyst inhibitors at a temperature that is greater than 5° C. abovethe polymerization temperature.

The most preferred thermally triggered compounds include4-p-hydroxyphenyl-2,2,4-trimethylthiachroman methanol clathrate thatchemically transforms into methanol and4-p-hydroxyphenyl-2,2,4-trimethylthiachroman; 2-pivaloypropionic acidthat chemically transforms into carbon dioxide (CO₂) and ketone;2-pivaloysuccinic acid that chemically transforms into carbon dioxideand ketone/carboxylic acid; benzoyl peroxide that chemically transformsinto carbon dioxide, benzene, benzoic acid and biphenyl among others;other clathrate complexes that melt and decompose between 60° C. and130° C.; other beta-keto carboxylic acids that melt and decomposebetween 60° C. and 130° C.; other organic peroxides melt and decomposebetween 60° C. and 130° C.; and various azobisorganonitriles that meltand decompose between 60° C. and 130° C. into nitrogen and a liquidorganic nitrile or other polar compound, preferably containing aheteroatom.

Methods for Using the Combination of Compounds

The use of the thermally triggered compound(s) of the invention canvary. For example, the thermally triggered compounds can be added orintroduced with or without a catalyst directly to a polymerizationprocess. The thermally triggered compounds may be combined prior tointroducing them to a polymerization process, or the thermally triggeredcompounds may be added separately and/or simultaneously to the reactor.In an embodiment, the thermally triggered compounds are contacted with acatalyst compound prior to being introduced to the reactor. Otherembodiments may include placing the thermally triggered compounds on asupport material and then introducing the support material to thepolymerization reactor, slurrying them in mineral oil and adding to thereactor separately as a slurry, or adding the solids directly to thereactor.

The thermally triggered compounds may be introduced in one embodiment inthe recycle stream of a gas phase polymerization process or below thedistributor plate or in a region within the reactor where the tendencyfor sheeting to occur is high. The details of a gas phase polymerizationprocess is discussed later in this patent specification.

In yet another embodiment, the thermally triggered compounds are used incombination with an unsupported catalyst system.

In the most preferred embodiment, thermally triggered compounds are usedwith a supported catalyst system. A most preferred method for making asupported catalyst system of the invention generally involves thecombining, contacting, blending, bonding and/or mixing any of the abovedescribed catalyst compounds, preferably a bulky ligand metallocenecatalyst compound, using any of the techniques previously described.

In one embodiment of the method of the invention, a catalyst compound iscombined, contacted, bonded, blended, and/or mixed with a thermallytriggered compounds. In a most preferred embodiment, the catalystcompound is a conventional-type transition metal catalyst and/or a bulkyligand metallocene catalyst supported on a carrier. In one embodiment,thermally triggered compounds are in a mineral oil slurry with orwithout a catalyst system, preferably with a supported catalyst systemthat is introduced to a polymerization process.

In another embodiment, the steps of the method of the invention includeforming a polymerization catalyst, preferably forming a supportedpolymerization catalyst, and contacting the polymerization catalyst,preferably the supported polymerization catalyst with a thermallytriggered compound. In a preferred method, the polymerization catalystcomprises a catalyst compound, an activator and a carrier, preferablythe polymerization catalyst is a supported bulky ligand metallocenecatalyst.

In one embodiment of the method of the invention, thermally triggeredcompounds, are contacted with the catalyst system, preferably asupported catalyst system, most preferably a supported bulky ligandmetallocene catalyst system under ambient temperatures and pressures.Preferably the contact temperature for combining the polymerizationcatalyst and the thermally triggered compounds is in the range of from0° C. to about 100° C., more preferably from 15° C. to about 75° C.,most preferably at about ambient temperature and pressure.

In a preferred embodiment, the contacting of the polymerization catalystand the thermally triggered compounds is performed under an inertgaseous atmosphere, such as nitrogen. However, it is contemplated thatthe combination of the polymerization catalyst and the thermallytriggered compounds may be performed in the presence of olefin(s),solvents, hydrogen and the like.

In one embodiment, the thermally triggered compounds may be added at anystage during the preparation. It is understood by those in the art thatin choosing a thermally triggered compound for example, that thecompound does not chemically transform during preparation of supportedcatalyst system.

In one embodiment of the method of the invention, the polymerizationcatalyst and a thermally triggered compound are combined in the presenceof a liquid, for example the liquid may be a mineral oil, toluene,hexane, isobutane or a mixture thereof. Ideally, the thermally triggeredcompound is largely insoluble in the liquid. In a more preferred methodthe thermally triggered compound is combined with a polymerizationcatalyst that has been formed in a liquid, preferably in a slurry, orcombined with a substantially dry or dried, polymerization catalyst thathas been placed in a liquid and reslurried.

Preferably, prior to use, the polymerization catalyst is contacted withthe thermally triggered compound for a period of time greater than asecond, preferably from about 1 minute to about 48 hours, morepreferably from about 10 minutes to about 10 hours, and most preferablyfrom about 30 minutes to about 6 hours. The period of contacting refersto the mixing time only.

In an embodiment, the mole ratio of the thermally triggered compounds tothe metal of the polymerization catalyst is the range from 5000 to about0.2, preferably from about 1000 to about 0.5, more preferably from about500 to about 1, and most preferably from about 250 to about 1.

In another embodiment, the weight ratio of the thermally triggeredcompound to the weight of the polymerization catalyst (including supportif a supported polymerization catalyst) is the range from 100 to 0.001,preferably from about 10 to about 0.01, more preferably from 5 to 0.1,and most preferably from 2 to about 0.2.

Mixing techniques and equipment contemplated for use in the method ofthe invention are well known. Mixing techniques may involve anymechanical mixing means, for example shaking, stirring, tumbling, androlling. Another technique contemplated involves the use offluidization, for example in a fluid bed reactor vessel where circulatedgases provide the mixing. Non-limiting examples of mixing equipment forcombining, a solid polymerization catalyst and thermally triggeredcompound include a ribbon blender, a static mixer, a double coneblender, a drum tumbler, a drum roller, a dehydrator, a fluidized bed, ahelical mixer and a conical screw mixer.

In a preferred embodiment of the invention a catalyst system issupported on a carrier, preferably the supported catalyst system issubstantially dried, preformed, substantially dry and/or free flowing.In an especially preferred method of the invention, the preformedsupported catalyst system is contacted with at least one thermallytriggered compound. The thermally triggered compound may be in solutionor slurry or in a dry state, preferably in a dry or dried state.

In an embodiment, the method of the invention provides for co-injectingan unsupported polymerization catalyst and the thermally triggeredcompound into the reactor. In one embodiment the polymerization catalystis used in the unsupported form, preferably in a liquid form such asdescribed in U.S. Pat. Nos. 5,317,036 and 5,693,727 and Europeanpublication EP-A-0 593 083, all of which are herein incorporated byreference. The polymerization catalyst in liquid form can be fed withthermally triggered compound together or separately to a reactor usingthe injection methods described in PCT publication WO 97/46599, which isfully incorporated herein by reference. Where an unsupported bulkyligand metallocene catalyst system is used the mole ratio of the metalof the activator component to the metal of the bulky ligand metallocenecatalyst compound is in the range of between 0.3:1 to 10,000:1,preferably 100:1 to 5000:1, and most preferably 500:1 to 2000:1.

In one embodiment, the polymerization catalyst has a productivitygreater than 1500 grams of polymer per gram of catalyst, preferablygreater than 2000 grams of polymer per gram of catalyst, more preferablygreater than 2500 grams of polymer per gram of catalyst and mostpreferably greater than 3000 grams of polymer per gram of catalyst. Inone embodiment, when the thermally triggered compound of the invention,react to form one or more, preferably two or more catalyst inhibitors,the polymerization catalyst productivity is reduced to less than 1500grams of polymer per gram of catalyst, preferably less than 1000 gramsof polymer per gram of catalyst, more preferably less than 500 grams ofpolymer per gram of catalyst, even more preferably less than 100 gramsof polymer per gram of catalyst, and still even more preferably lessthan 25 grams of polymer per gram of catalyst and most preferably toless than is measurably possible or 0 grams of polymer per gram ofcatalyst.

Polymerization Process

The catalyst system including the thermally triggered compound of theinvention described above are suitable for use in any prepolymerizationand/or polymerization process over a wide range of temperatures andpressures. The temperatures may be in the range of from −60° C. to about280° C., preferably from 50° C. to about 200° C., and the pressuresemployed may be in the range from 1 atmosphere to about 500 atmospheresor higher.

Polymerization processes include solution, gas phase, slurry phase and ahigh pressure process or a combination thereof. Particularly preferredis a gas phase or slurry phase polymerization of one or more olefins atleast one of which is ethylene or propylene.

In one embodiment, the process of this invention is directed toward asolution, high pressure, slurry or gas phase polymerization process ofone or more olefin monomers having from 2 to 30 carbon atoms, preferably2 to 12 carbon atoms, and more preferably 2 to 8 carbon atoms. Theinvention is particularly well suited to the polymerization of two ormore olefin monomers of ethylene, propylene, butene-1,pentene-1,4-methyl-pentene-1, hexene-1, octene-1 and decene-1.

Other monomers useful in the process of the invention includeethylenically unsaturated monomers, diolefins having 4 to 18 carbonatoms, conjugated or nonconjugated dienes, polyenes, vinyl monomers andcyclic olefins. Non-limiting monomers useful in the invention mayinclude norbornene, norbornadiene, isobutylene, isoprene,vinylbenzocyclobutane, styrenes, alkyl substituted styrene, ethylidenenorbornene, dicyclopentadiene and cyclopentene.

In the most preferred embodiment of the process of the invention, acopolymer of ethylene is produced, where with ethylene, a comonomerhaving at least one alpha-olefin having from 4 to 15 carbon atoms,preferably from 4 to 12 carbon atoms, and most preferably from 4 to 8carbon atoms, is polymerized in a gas phase process.

In another embodiment of the process of the invention, ethylene orpropylene is polymerized with at least two different comonomers,optionally one of which may be a diene, to form a terpolymer.

In one embodiment, the invention is directed to a polymerizationprocess, particularly a gas phase or slurry phase process, forpolymerizing propylene alone or with one or more other monomersincluding ethylene, and/or other olefins having from 4 to 12 carbonatoms. Polypropylene polymers may be produced using the particularlybridged bulky ligand metallocene catalysts as described in U.S. Pat.Nos. 5,296,434 and 5,278,264, both of which are herein incorporated byreference.

Typically in a gas phase polymerization process a continuous cycle isemployed where in one part of the cycle of a reactor system, a cyclinggas stream, otherwise known as a recycle stream or fluidizing medium, isheated in the reactor by the heat of polymerization. This heat isremoved from the recycle composition in another part of the cycle by acooling system external to the reactor. Generally, in a gas fluidizedbed process for producing polymers, a gaseous stream containing one ormore monomers is continuously cycled through a fluidized bed in thepresence of a catalyst under reactive conditions. The gaseous stream iswithdrawn from the fluidized bed and recycled back into the reactor.Simultaneously, polymer product is withdrawn from the reactor and freshmonomer is added to replace the polymerized monomer. (See for exampleU.S. Pat. Nos. 4,543,399, 4,588,790, 5,028,670, 5,317,036, 5,352,749,5,405,922, 5,436,304, 5,453,471, 5,462,999, 5,616,661 and 5,668,228, allof which are fully incorporated herein by reference.)

The reactor pressure in a gas phase process may vary from about 100 psig(690 kPa) to about 500 psig (3448 kPa), preferably in the range of fromabout 200 psig (1379 kPa) to about 400 psig (2759 kPa), more preferablyin the range of from about 250 psig (1724 kPa) to about 350 psig (2414kPa).

The reactor temperature in a gas phase process may vary from about 30°C. to about 120° C., preferably from about 60° C. to about 115° C., morepreferably in the range of from about 70° C. to 110° C., and mostpreferably in the range of from about 70° C. to about 95° C. Forpurposes of this patent specification and appended claims the terms“polymerization temperature” and “reactor temperature” areinterchangeable.

Other gas phase processes contemplated by the process of the inventioninclude series or multistage polymerization processes. Also gas phaseprocesses contemplated by the invention include those described in U.S.Pat. Nos. 5,627,242, 5,665,818 and 5,677,375, and European publicationsEP-A-0 794 200 EP-B 1-0 649 992, EP-A-0 802 202 and EP-B-634 421 all ofwhich are herein fully incorporated by reference.

In a preferred embodiment, the reactor utilized in the present inventionis capable and the process of the invention is producing greater than500 lbs of polymer per hour (227 Kg/hr) to about 200,000 lbs/hr (90,900Kg/hr) or higher of polymer, preferably greater than 1000 lbs/hr (455Kg/hr), more preferably greater than 10,000 lbs/hr (4540 Kg/hr), evenmore preferably greater than 25,000 lbs/hr (11,300 Kg/hr), still morepreferably greater than 35,000 lbs/hr (15,900 Kg/hr), still even morepreferably greater than 50,000 lbs/hr (22,700 Kg/hr) and most preferablygreater than 65,000 lbs/hr (29,000 Kg/hr) to greater than 100,000 lbs/hr(45,500 Kg/hr).

A slurry polymerization process generally uses pressures in the range offrom about 1 to about 50 atmospheres and even greater and temperaturesin the range of 0° C. to about 120° C. In a slurry polymerization, asuspension of solid, particulate polymer is formed in a liquidpolymerization diluent medium to which ethylene and comonomers and oftenhydrogen along with catalyst are added. The suspension including diluentis intermittently or continuously removed from the reactor where thevolatile components are separated from the polymer and recycled,optionally after a distillation, to the reactor. The liquid diluentemployed in the polymerization medium is typically an alkane having from3 to 7 carbon atoms, preferably a branched alkane. The medium employedshould be liquid under the conditions of polymerization and relativelyinert. When a propane medium is used the process must be operated abovethe reaction diluent critical temperature and pressure. Preferably, ahexane or an isobutane medium is employed. In such slurrypolymerizations, it is preferred that the thermally triggered compoundbe largely insoluble in the medium.

A preferred polymerization technique of the invention is referred to asa particle form polymerization, or a slurry process where thetemperature is kept below the temperature at which the polymer goes intosolution. Such technique is well known in the art, and described in forinstance U.S. Pat. No. 3,248,179 which is fully incorporated herein byreference. Other slurry processes include those employing a loop reactorand those utilizing a plurality of stirred reactors in series, parallel,or combinations thereof. Non-limiting examples of slurry processesinclude continuous loop or stirred tank processes. Also, other examplesof slurry processes are described in U.S. Pat. No. 4,613,484, which isherein fully incorporated by reference.

In an embodiment the reactor used in the slurry process of the inventionis capable of and the process of the invention is producing greater than2000 lbs of polymer per hour (907 Kg/hr), more preferably greater than5000 lbs/hr (2268 Kg/hr), and most preferably greater than 10,000 lbs/hr(4540 Kg/hr). In another embodiment the slurry reactor used in theprocess of the invention is producing greater than 15,000 lbs of polymerper hour (6804 Kg/hr), preferably greater than 25,000 lbs/hr (11,340Kg/hr) to about 100,000 lbs/hr (45,500 Kg/hr).

Examples of solution processes are described in U.S. Pat. Nos.4,271,060, 5,001,205, 5,236,998 and 5,589,555, which are fullyincorporated herein by reference

A preferred process of the invention is where the process, preferably aslurry or gas phase process is operated in the presence of a bulkyligand metallocene catalyst system of the invention and in the absenceof or essentially free of any scavengers, such as triethylaluminum,trimethylaluminum, tri-isobutylaluminum and tri-n-hexylaluminum anddiethyl aluminum chloride, dibutyl zinc and the like. This preferredprocess is described in PCT publication WO 96/08520 and U.S. Pat. Nos.5,712,352 and 5,763,543, which are herein fully incorporated byreference.

Polymer Product of the Invention

The polymers produced by the process of the invention can be used in awide variety of products and end-use applications. The polymers producedby the process of the invention include linear low density polyethylene,elastomers, plastomers, high density polyethylenes, low densitypolyethylenes, polypropylene and polypropylene copolymers.

The polymers, typically ethylene based polymers, have a density in therange of from 0.86 g/cc to 0.97 g/cc, preferably in the range of from0.88 g/cc to 0.965 g/cc, more preferably in the range of from 0.900 g/ccto 0.96 g/cc, even more preferably in the range of from 0.905 g/cc to0.95 g/cc, yet even more preferably in the range from 0.910 g/cc to0.940 g/cc, and most preferably greater than 0.915 g/cc, preferablygreater than 0.920 g/cc, and most preferably greater than 0.925 g/cc.Density is measured in accordance with ASTM-D-1238.

The polymers produced by the process of the invention typically have amolecular weight distribution, a weight average molecular weight tonumber average molecular weight (M_(w)/M_(n)) of greater than 1.5 toabout 30, particularly greater than 2 to about 10, more preferablygreater than about 2.2 to less than about 8, and most preferably from2.5 to 8.

Also, the polymers of the invention typically have a narrow compositiondistribution as measured by Composition Distribution Breadth Index(CDBI). Further details of determining the CDBI of a copolymer are knownto those skilled in the art. See, for example, PCT Patent Application WO93/03093, published Feb. 18, 1993, which is fully incorporated herein byreference.

The bulky ligand metallocene catalyzed polymers of the invention in oneembodiment have CDBI's generally in the range of greater than 50% to100%, preferably 99%, preferably in the range of 55% to 85%, and morepreferably 60% to 80%, even more preferably greater than 60%, still evenmore preferably greater than 65%.

In another embodiment, polymers produced using a bulky ligandmetallocene catalyst system of the invention have a CDBI less than 50%,more preferably less than 40%, and most preferably less than 30%.

The polymers of the present invention in one embodiment have a meltindex (MI) or (I₂) as measured by ASTM-D-1238-E in the range from 0.01dg/min to 1000 dg/min, more preferably from about 0.01 dg/min to about100 dg/min, even more preferably from about 0.1 dg/min to about 50dg/min, and most preferably from about 0.1 dg/min to about 10 dg/min.

The polymers of the invention in an embodiment have a melt index ratio(I₂₁/I₂) (I₂₁ is measured by ASTM-D-1238-F) of from 10 to less than 25,more preferably from about 15 to less than 25.

The polymers of the invention in a preferred embodiment have a meltindex ratio (I₂₁/I₂) (I₂₁ is measured by ASTM-D-1238-F) of frompreferably greater than 25, more preferably greater than 30, even morepreferably greater that 40, still even more preferably greater than 50and most preferably greater than 65.

In an embodiment, the polymer of the invention may have a narrowmolecular weight distribution and a broad composition distribution orvice-versa, and may be those polymers described in U.S. Pat. No.5,798,427 incorporated herein by reference.

In yet another embodiment, propylene based polymers are produced in theprocess of the invention. These polymers include atactic polypropylene,isotactic polypropylene, hemi-isotactic and syndiotactic polypropylene.Other propylene polymers include propylene block or impact copolymers.Propylene polymers of these types are well known in the art see forexample U.S. Pat. Nos. 4,794,096, 3,248,455, 4,376,851, 5,036,034 and5,459,117, all of which are herein incorporated by reference.

The polymers of the invention may be blended and/or coextruded with anyother polymer. Non-limiting examples of other polymers include linearlow density polyethylenes produced via conventional Ziegler-Natta and/orbulky ligand metallocene catalysis, elastomers, plastomers, highpressure low density polyethylene, high density polyethylenes,polypropylenes and the like. Polymers produced by the process of theinvention and blends thereof are useful in such forming operations asfilm, sheet, and fiber extrusion and co-extrusion as well as blowmolding, injection molding and rotary molding. Films include blown orcast films formed by coextrusion or by lamination useful as shrink film,cling film, stretch film, sealing films, oriented films, snackpackaging, heavy duty bags, grocery sacks, baked and frozen foodpackaging, medical packaging, industrial liners, membranes, etc. infood-contact and non-food contact applications. Fibers include meltspinning, solution spinning and melt blown fiber operations for use inwoven or non-woven form to make filters, diaper fabrics, medicalgarments, geotextiles, etc. Extruded articles include medical tubing,wire and cable coatings, geomembranes, and pond liners. Molded articlesinclude single and multi-layered constructions in the form of bottles,tanks, large hollow articles, rigid food containers and toys, etc.

EXAMPLES

In order to provide a better understanding of the present inventionincluding representative advantages thereof, the following examples areoffered.

The polymerization catalyst used in the examples below was preparedsimilarly to the following preparation. The bridged, bulky ligandmetallocene catalyst compound wasdimethylsilyl-bis(tetrahydroindenyl)zirconium dichloride(Me₂Si(H₄Ind)₂ZrCl₂) available from Albemarle Corporation, Baton Rouge,La. The (Me₂Si(H₄Ind)₂ZrCl₂) catalyst compound was supported onCrosfield ES-70 grade silica dehydrated at 600° C. having approximately1.0 weight percent water Loss on Ignition (LOI). LOI is measured bydetermining the weight loss of the support material which has beenheated and held at a temperature of about 1000° C. for about 22 hours.The Crosfield ES-70 grade silica has an average particle size of 40microns and is available from Crosfield Limited, Warrington, England.

The first step in the manufacture of the supported bulky ligandmetallocene catalyst above involves forming a precursor solution. 460lbs (209 kg) of sparged and dried toluene is added to an agitatedreactor after which 1060 lbs (482 kg) of a 30 weight percentmethylaluminoxane (MAO) in toluene (available from Albemarle, BatonRouge, La.) is added. 947 lbs (430 kg) of a 2 weight percent toluenesolution of a dimethylsilyl-bis(tetrahydroindenyl) zirconium dichloridecatalyst compound and 600 lbs (272 kg) of additional toluene areintroduced into the reactor. The precursor solution is then stirred at80° F. to 100° F. (26.7° C. to 37.8° C.) for one hour.

While stirring the above precursor solution, 850 lbs (386 kg) of 600° C.Crosfield dehydrated silica carrier is added slowly to the precursorsolution and the mixture agitated for 30 min. at 80° F. to 100° F. (26.7to 37.8° C.). At the end of the 30 min. agitation of the mixture, 240lbs (109 kg) of a 10 weight percent toluene solution of AS-990(N,N-bis(2-hydroxylethyl) octadecylamine ((C₁₈H₃₇N(CH₂CH₂OH)₂) availableas Kemamine AS-990 from Witco Corporation, Memphis, Tennessee, is addedtogether with an additional 110 lbs (50 kg) of a toluene rinse and thereactor contents then is mixed for 30 min. while heating to 175° F. (79°C.). After 30 min. vacuum is applied and the polymerization catalystmixture dried at 175° F. (79° C.) for about 15 hours to a free flowingpowder. The final polymerization catalyst weight was 1200 lbs (544 kg)and had a Zr wt % of 0.35 and an Al wt % of 12.0.

Example 1

Synthesis of 4-p-hydroxyphenyl-2,2,4-trimethylthiachroman

The compound “MeOH Clathrate” is4-p-hydroxyphenyl-2,2,4-trimethylthiachroman methanol hydrate. It wassynthesized by the method outlined by MacNicol, D. D. Chem.Communications 1969, 836.

Example 2

Synthesis of 2-Pivaloylpropionic Acid

Ethyl 2-pivaloylpropionate. A 500 mL 3-neck round-bottom flask wasequipped with a reflux condensor and thermometer and purged withnitrogen. To it was charged 100 mL dry, deoxygenated diethyl ether and4.4 g of zinc strips. This mixture was agitated in a water-filledsonicating bath for 5 minutes. To this was slowly added a mixture of12.06 g pivaloyl chloride (0.10 mole), 18.1 g of ethyl 2-bromopropionate(0.10 mole, synthesized by the method of Strunk, R. J.; DiGiacomo, P.M.; Aso, K.; Kuivila, H. G. J Am. Chem. Soc., 1970, 92, 2849-2856.) and100 mL of ethyl ether. The resulting mixture was refluxed 6 hours andstirred at room temperature overnight. The mixture was then successivelyextracted with cold 20% aqueous sulfuric acid, water and brine beforedrying over sodium sulfate. The solution was stripped to obtain 12.8 gof crude oil. This was distilled under vacuum to yield 10.5 g of ethyl2-pivaloylpropionate. ¹H NMR (CDCl₃): δ4.103 (q, J=7.1 Hz, 2H), 3.959(q, J=6.9, 1 Hz), 1.287 (d, J=7.0 Hz, 3H), 1.196 (t, J=7.1 Hz, 3H),1.157 (s, 9H).

2-Pivaloylpropionic acid. A 5 g portion of ethyl 2-pivaloylpropionatewas stirred with 1M aqueous lithium hydroxide overnight. Afteracidification with 37% hydrochloric acid, the mixture was extracted withether. The organic extracts were washed with water and then brine toyield 3.5 g of solid. Recrystallization from pentane yielded 2.0 g ofpure 2-pivaloylpropionic acid. M.P.: 100-102° C. (decomp.). ¹H NMR(CDCl₃): δ4.024 (q, J=7.0 Hz, 1H), 1.316 (d, J=7.0 Hz, 3H), 1.177 (s,9H).

Example 3

Synthesis of 2-Pivaloylsuccinic Acid

Ethyl 2-pivaloylsuccinate. A 500 mL 3-neck round-bottom flask wasequipped with a reflux condensor and thermometer and purged withnitrogen. To it was charged 100 mL dry, deoxygenated diethyl ether and4.4 g of zinc strips. This mixture was agitated in a water-filledsonicating bath for 5 minutes. To this was slowly added a mixture of 8.0g of pivaloyl chloride (0.066 mole), 14.0 g of 2-bromosuccinic acid(0.061 mole, synthesized by the method of Fenton J. Chem. Soc. 1898,72-73.) and 100 mL of ethyl ether. The resulting mixture was refluxed 6hours and stirred at room temperature overnight. The mixture was thensuccessively extracted with cold 20% aqueous sulfuric acid, water andbrine before drying over sodium sulfate. The solution was stripped toobtain 14.6 g of crude oil. This was distilled under vacuum to yield12.1 g of ethyl 2-pivaloylsuccinate. ¹H NMR (CDCl₃): δ4.341 (q, J=7.3Hz, 1H), 4.116 (q, J=7.1 Hz, 2H), 4.082 (q, J=7.3 Hz, 2H), 2.792 (d,J=7.2 Hz, 2H), 1.204 (t, J=7.2 Hz, 3H), 1.203 (t, J=7.1 Hz, 3H), 1.177(s, 9H).

2-Pivaloylsuccinic acid. A 3.5 g portion of ethyl 2-pivaloylsuccinatewas stirred with 1 M aqueous lithium hydroxide overnight. Afteracidification with 37% hydrochloric acid, the mixture was extracted withether. The organic extracts were washed with water and then brine toyield 1.5 g of solid. Recrystallization from pentane/diethyl etheryielded 1.0 g of pure 2-pivaloylsuccinic acid. M.P.: 115° C. (decomp.).¹H NMR (CDCl₃): δ4.229 (t, J=7.3 Hz, 1H), 2.694 (dd, J=17.2, 6.6 Hz,1H), 2.670 (dd, J=17.2, 7.7 Hz, 1H), 1.093 (s, 9H).

Polymerization Process

A one liter 316 Stainless Steel (SS) reactor with air-operated helicalstirrer and an outer steam-heated shell and a inner acetoneheat-transfer shell was dried by heating to 115° C. while purging with500 sccm of nitrogen for 30 minutes. After cooling to 90° C., it wascharged with 100 g of polyethylene (granular Union Carbide grade DSX4810(available from Union Carbide Corporation, Danbury, Conn.), Cr-based,0.948 density, I₁₀=10, unstabilized) under inert conditions. A catalystcharging vessel comprising a ¼ inch (0.64 cm)×2″ (5 cm) stainless steeltube isolated between two ball valves, charged with 60 mg supportedpolymerization catalyst (2 μmol zirconium) in a drybox, was attached tothe reactor against a nitrogen purge. A similar vessel containing thethermally triggered compound (if any) was attached in the same way. Thereactor was then pressure/vented four times with 100 psi (690 kPa)nitrogen. A solution of 100 micromoles of tri-isobutylaluminum (TIBA)was then added and the reactor sealed and pressure/vented three timeswith 100 psi (690 kPa) ethylene before bringing the reactor to reactorconditions, 107 psi (738 kPa) and 60, 80 or 90° C. as detailed below.

When the reactor stabilized, the catalyst was injected. Thermallytriggered compound, if any, was injected at 20 minutes. After 38 minutesthe temperature was ramped to 100° C. during 5 minutes and held for 40minutes. The ideal thermally triggered compound for purposes of theseexperiments below will have little effect on the catalyst activity atthe initial temperature but will substantially reduce catalyst activityat the higher temperature.

Comparative Examples 4 to 7 (CEX. 4 to 7)

Control Experiments

These Comparative Examples 4 to 7 are control experiments, where nothermally triggered compound was used with the polymerization catalyst.Table 1 illustrates that without the thermally triggered compound,catalyst activity is substantially higher at the higher temperaturerange, 100° C. in these examples.

Example 8

4.8 mg of diketosuccinic acid was charged to the catalyst chargingvessel and injected with nitrogen pressure at 20 minutes during the 80°C. segment of the run. Table 1 illustrates that catalyst activity issubstantially reduced at the higher temperature range.

Example 9

As in Example 8 above except that 10.2 mg of 2-pivaloylsuccinic acid wasused in place of diketosuccinic acid. Table 1 illustrates that catalystactivity is substantially reduced at the higher temperature range.

Example 10

As in Example 8 above except that 8.4 mg of 2-pivaloylsuccinic acid wasused in place of diketosuccinic acid. Table 1 illustrates that catalystactivity is substantially reduced at the higher temperature range.

Example 11

As in Example 8 above except that 1.8 mg of 2-pivaloylsuccinic acid wasused in place of diketosuccinic acid. Table 1 illustrates that catalystactivity is substantially reduced at the higher temperature range.

Example 12

As in Example 8 above except that 10.2 mg of 2-pivaloylpropionic acidwas used in place of diketosuccinic acid. Table 1 illustrates thatcatalyst activity is substantially reduced at the higher temperaturerange.

Example 13

As in Example 8 above except that 32 mg of clathrate complex fromExample 1 was used in place of diketosuccinic acid. Table 1 illustratesthat catalyst activity is substantially reduced at the highertemperature range.

TABLE 1 (g) uptake (g) uptake uptake Example Thermally TriggeredInhbitor Activity¹ 80° C. 100° C. 100° C./80° C. CEX. 4 None 14990 16.536.9 2.23 CEX. 5 None 13484 17.0 38.6 2.27 CEX. 6 None 12584 15.4 30.41.98 CEX. 7 None 13216 13.6 28.0 2.06  8 4.8 mg diketosuccinic acid   6022 13.4 9.2 0.69  9 10.2 mg 2-pivaloylsuccinic acid  1686 9.5 3.0 0.3210 8.4 mg 2-pivaloylsuccinic acid 2411 6.8 1.7 0.25 11 1.8 mg2-pivaloylsuccinic acid 7182 13.2 11.6 0.88 12 10.2 mg2-pivaloylpropionic acid 3983 11.7 7.3 0.62 13 32 mg MeOH clathrate   6262 10.4 10.7 1.03 ¹Activity is measured as grams of polyethylene/mmolZr/hour/100 psi (690 kPa) ethylene

Comparative Examples 14 to 16 (CEX. 14 to 16)

Control Experiments

These Comparative Examples 14 to 16 are control experiments, where nothermally triggered compound was used with the polymerization catalystand run like those in Comparative Examples 4 to 7 except that thetemperature range spans 90° C. to 110° C. Table 2 illustrates thatwithout the thermally triggered compound, catalyst activity issubstantially higher at the higher temperature range, 110° C. in theseexamples.

Example 17

As in Example 8 above except that 4.5 mg of diketosuccinic acid was usedat a temperature range of 90 to 110° C. Table 2 illustrates thatcatalyst activity is substantially reduced at the higher temperaturerange.

Example 18

As in Example 8 above except that 1.7 mg of diketosuccinic acid was usedat a temperature range of 90 to 110° C. Table 2 illustrates thatcatalyst activity is substantially reduced at the higher temperaturerange.

TABLE 2 (g) uptake (g) uptake Uptake Example Thermally TriggeredInhibitor Activity¹ 90° C. 110° C. 110° C./90° C. CEX. 14 None 1600929.3 33.1 1.13 CEX. 15 None 16151 30.3 28.4 0.94 CEX. 16 None 15981 28.129.5 1.05 17 4.5 mg diketosuccinic acid 6050 18.2 4.6 0.25 18 1.7 mgdiketosuccinic acid 8484 23.1 14.4 0.62 ¹Activity is measured as gramsof polyethylene/mmol Zr/hour/100 psi (690 kPa) ethylene

Comparative Examples 19 to 21

Control Experiments

These Comparative Examples 19 to 21 are control experiments, where nothermally triggered compound was used with the polymerization catalyst,and were run like those in Comparative Examples 4 to 7 above except thatthe temperature range spans 60° C. to 100° C. Table 3 illustrates thatwithout the control agent, catalyst activity is substantially higher atthe higher temperature range, 100° C. in these examples.

Examples 22 to 23

As in Example 8 above, except that 6 mg of benzoyl peroxide was used inplace of the diketosuccinic acid, and the temperature range was 40° C.to 100° C. Table 3 illustrates that catalyst activity is substantiallyreduced at the higher temperature range.

TABLE 3 (g) uptake (g) uptake Uptake Example control agent umol ZrActivity¹ 60° C. 100° C. 100° C./60° C. 19 control 4.1 6644 6.5 39.96.15 20 control 3.1 6374 3.7 29.8 8.08 21 control 3.0 4147 3.3 18.0 5.4022 6 mg benzoyl peroxide 5.1 1043 4.8 2.4 0.51 23 6 mg benzoyl peroxide5.0 977 5.3 5.7 1.07 ¹Activity is measured as grams of polyethylene/mmolZr/hour/100 psi (690 kPa) ethylene

While the present invention has been described and illustrated byreference to particular embodiments, those of ordinary skill in the artwill appreciate that the invention lends itself to variations notnecessarily illustrated herein. For example, it is contemplated thatdifferent thermally triggered compounds, or a different combination ofthermally triggered compounds may be used during the polymerizationprocess depending on the product being produced. Also, two or morepolymerization reactors, in series or parallel, slurry and/or gas phasemay be used in which different combinations of thermally triggeredcompounds may be used. Furthermore, the thermally triggered compoundsmay be utilized downstream of the reactor to deactivate polymerwithdrawn from a polymerization reactor. In addition, the thermallytriggered compound may be used during the transition from one polymergrade to another. Also, two or more polymerization catalysts may be usedwith the thermally triggered compound of the invention. For this reason,then, reference should be made solely to the appended claims forpurposes of determining the true scope of the present invention.

We claim:
 1. A catalyst composition comprising a polymerization catalystand a thermally triggered compound that at a specified temperaturechemically transforms into one or more catalyst inhibitors thatdeactivate the catalyst composition.
 2. The catalyst composition ofclaim 1 wherein the catalyst inhibitors are formed at a temperaturedifferent from the specified temperature.
 3. The catalyst composition ofclaim 1 wherein the specified temperature is greater than apolymerization temperature.
 4. The catalyst composition of claim 1wherein the polymerization catalyst is supported.
 5. The catalystcomposition of claim 1 wherein the thermally triggered compound has aweight loss of greater than 5 weight percent at 100° C. measured usingthermogravimetric analysis at 100° C. for 20 minutes.
 6. The catalystcomposition of claim 1 wherein the thermally triggered compound has aweight loss between greater than 5 weight percent at 100° C. and lessthan 0.02 weight percent at 80° C. as measured using thermogravimetricanalysis at 80° C. for 20 minutes and 100° C. for 20 minutes.
 7. Thecatalyst composition of claim 1 wherein at least one catalyst inhibitoris a gas or vapor.
 8. The catalyst composition of claim 7 wherein thethermally triggered compound is a solid beta-keto acid.
 9. The catalystcomposition of claim 1 wherein two catalyst inhibitors are formed onebeing a gas or vapor and the other being a liquid.
 10. The catalystcomposition of claim 9 wherein one of the catalyst inhibitors is carbondioxide and the other is a ketone.
 11. A catalyst composition comprisinga bulky ligand metallocene catalyst compound, an activator, a support, athermally triggered compound, wherein thermally triggered compound isunreactive to the catalyst composition at 25° C.
 12. The catalystcomposition of claim 11 wherein if the catalyst composition is heated togreater than 80° C., the thermally triggered compound chemicallytransforms into at least one catalyst inhibitor.
 13. The catalystcomposition of claim 11 wherein the catalyst composition is heated bythe heat of a polymerization process in excess of the operatingtemperature of the process.